Update uses of WebContentsConsoleObserver::Wait to check return value.

The return value is newly-added and will be marked [[nodiscard]] as
soon as all uses are updated.

Previous CLs update under content/ but nothing outside of content/.

BUG=1379192

This CL was uploaded by git cl split.

R=estark@chromium.org

Change-Id: I1f473d0ab430430e7aa51f618995f4db4d95d49a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3988239
Reviewed-by: Trent Apted <tapted@chromium.org>
Commit-Queue: Trent Apted <tapted@chromium.org>
Auto-Submit: Fergal Daly <fergal@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1066268}
diff --git a/chrome/browser/ui/login/login_handler_browsertest.cc b/chrome/browser/ui/login/login_handler_browsertest.cc
index bc987aa..b5c86a6b1 100644
--- a/chrome/browser/ui/login/login_handler_browsertest.cc
+++ b/chrome/browser/ui/login/login_handler_browsertest.cc
@@ -2209,7 +2209,7 @@
   GURL test_page = embedded_test_server()->GetURL(kSlowResponse);
   ASSERT_TRUE(ui_test_utils::NavigateToURL(browser(), test_page));
 
-  console_observer.Wait();
+  ASSERT_TRUE(console_observer.Wait());
   ASSERT_EQ(1u, console_observer.messages().size());
   EXPECT_EQ(u"onAuthRequired " + base::ASCIIToUTF16(test_page.spec()),
             console_observer.messages()[0].message);